Package daikon.chicory

Class Instrument

Object

StackMapUtils

InstructionListUtils

Instrument

All Implemented Interfaces:

ClassFileTransformer

public class Instrument
extends InstructionListUtils
implements ClassFileTransformer

This class is responsible for modifying another class's bytecodes. Specifically, its main task is to add calls into the Chicory runtime at method entries and exits for instrumentation purposes. These added calls are sometimes referred to as "hooks".

This class is loaded by ChicoryPremain at startup. It is a ClassFileTransformer which means that its transform method gets called each time the JVM loads a class.

Field Summary

Fields

Modifier and Type	Field	Description
static SimpleLog	debug_ppt_omit	Debug information about ppt-omit and ppt-select.
protected static SimpleLog	debug_transform	Debug information about which classes and/or methods are transformed and why.
InstructionFactory	instFactory	InstructionFactory for a class.

Fields inherited from class StackMapUtils

debugInstrument, firstLocalIndex, initialLocalsCount, initialTypeList, liveRangeEnd, liveRangeOperandSize, liveRangeStart, liveRangeType, needStackMap, numberActiveLocals, pool, runningOffset, smta, stackMapTable, stackTypes

Constructor Summary

Constructors

Constructor	Description
Instrument()	Create an instrumenter.

Method Summary

Modifier and Type	Method	Description
void	dump_code_attributes(MethodGen mgen)	Logs a method's attributes.
static boolean	shouldIgnore(@BinaryName String className, String methodName, String pptName)	Returns true if the given ppt should be ignored.
byte @Nullable []	transform(@Nullable ClassLoader loader, @InternalForm String className, @Nullable Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer)	Given a class, return a transformed version of the class that contains instrumentation code.

Methods inherited from class InstructionListUtils

append_inst, build_il, calculateLiveLocalTypes, calculateLiveStackTypes, delete_instructions, insertAtMethodStart, insertBeforeHandle, replaceInstructions

Methods inherited from class StackMapUtils

addNewParameter, addString, adjust_code_for_locals_change, bcelCalcStackTypes, buildUninitializedNewMap, create_local_from_live_range, create_method_scope_local, createNewStackMapAttribute, findStackMapEqual, findStackMapIndexAfter, findStackMapIndexBefore, fixLocalVariableTable, gen_locals, gen_locals_from_byte_codes, gen_locals_from_byte_codes, generate_Type_from_StackMapType, generateStackMapTypeFromType, get_attribute_name, get_local_variable_type_table_attribute, getSize, getStackMapTable_attribute, is_local_variable_type_table, isStackMapTable, modifyStackMapsForSwitches, printStackMapTable, remove_local_variable_type_table, set_method_stackTypes, setCurrentStackMapTable, typeToClassGetName, update_full_frameStackMap_entries, updateStackMapOffset, updateUninitializedNewOffsets

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ClassFileTransformer

transform

Field Detail

debug_transform

protected static final SimpleLog debug_transform

Debug information about which classes and/or methods are transformed and why.

debug_ppt_omit

public static final SimpleLog debug_ppt_omit

Debug information about ppt-omit and ppt-select.

instFactory

public InstructionFactory instFactory

InstructionFactory for a class.

Constructor Detail

Instrument

public Instrument()

Create an instrumenter. Setup debug directories, if needed.

Method Detail

shouldIgnore

public static boolean shouldIgnore(@BinaryName String className,
                                   String methodName,
                                   String pptName)

Returns true if the given ppt should be ignored. Uses the patterns in Runtime.ppt_omit_pattern and Runtime.ppt_select_pattern. This method is used by both Chicory and Dyncomp.

Parameters:

className - class name to be checked

methodName - method name to be checked

pptName - ppt name to be checked

Returns:

true if the item should be filtered out

transform

public byte @Nullable [] transform(@Nullable ClassLoader loader,
                                   @InternalForm String className,
                                   @Nullable Class<?> classBeingRedefined,
                                   ProtectionDomain protectionDomain,
                                   byte[] classfileBuffer)
                            throws IllegalClassFormatException

Given a class, return a transformed version of the class that contains instrumentation code. Because Chicory is invoked as a javaagent, the transform method is called by the Java runtime each time a new class is loaded. A return value of null leaves the byte codes unchanged.

Specified by:

transform in interface ClassFileTransformer

Throws:

IllegalClassFormatException

dump_code_attributes

public void dump_code_attributes(MethodGen mgen)

Logs a method's attributes.

Parameters:

mgen - describes the given method